Trackpad on back portion of a device

ABSTRACT

Aspects of the present disclosure involve a system and a method for performing operations comprising: detecting physical touch of a touch-sensitive component on a back portion of a client device, the client device displaying a graphical user interface on a touch-sensitive display screen of a front portion of the client device; in response to detecting the physical touch, transmitting an electrical signal representing the physical touch of the touch-sensitive component on the back portion of the client device to the touch-sensitive display screen of the front portion of the client device; and causing an operation associated with the graphical user interface to be executed in response to the touch-sensitive display screen receiving the electrical signal representing the physical touch of the touch-sensitive component on the back portion of the client device.

CLAIM OF PRIORITY

This application is a continuation of U.S. application Ser. No.17/318,806, filed on May 12, 2021, which claims the benefit of priorityto U.S. Provisional Application Ser. No. 63/024,696, filed on May 14,2020, which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates generally to touchscreen navigation andoperation of a user device.

BACKGROUND

Touchscreens are the primary way users operate mobile devices. Thetouchscreens allow a user to directly touch on a portion of a screen onwhich certain content is presented to control and interact with suchcontent. For example, a user can be presented with a webpage on thetouchscreen and swipe up/down to scroll the webpage and touch differentportions to select different options presented on the webpage.Touchscreens also present keyboards with virtual keys a user can tap tocompose messages and provide textual input to the mobile device. Usingtouchscreens devices can use the same component to output content (via adisplay) and receive physical input of commands from a user.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. To easily identifythe discussion of any particular element or act, the most significantdigit or digits in a reference number refer to the figure number inwhich that element is first introduced. Some embodiments are illustratedby way of example, and not limitation, in the figures of theaccompanying drawings in which:

FIG. 1 is a diagrammatic representation of a networked environment inwhich the present disclosure may be deployed, in accordance with someexamples.

FIG. 2 is a diagrammatic representation of a messaging system, inaccordance with some examples, that has both client-side and server-sidefunctionality.

FIG. 3 is a diagrammatic representation of a data structure asmaintained in a database, in accordance with some examples.

FIG. 4 is a diagrammatic representation of a message, in accordance withsome examples.

FIG. 5 is a diagrammatic representation of remote interaction with atouchscreen, in accordance with some examples.

FIGS. 6-9 are diagrammatic representations of various embodiments of aclient device with a trackpad on the back of the client device, inaccordance with some examples.

FIG. 10 is a flowchart illustrating example operations of the clientdevice with a trackpad on the back of the client device, according toexample embodiments.

FIG. 11 is a diagrammatic representation of a machine in the form of acomputer system within which a set of instructions may be executed forcausing the machine to perform any one or more of the methodologiesdiscussed herein, in accordance with some examples.

FIG. 12 is a block diagram showing a software architecture within whichexamples may be implemented.

DETAILED DESCRIPTION

The description that follows includes systems, methods, techniques,instruction sequences, and computing machine program products thatembody illustrative embodiments of the disclosure. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide an understanding of variousembodiments. It will be evident, however, to those skilled in the art,that embodiments may be practiced without these specific details. Ingeneral, well-known instruction instances, protocols, structures, andtechniques are not necessarily shown in detail.

Many typical devices operate using touchscreens. Such devices presentcontent on the touchscreens and allow a user to input commands andinteract with the devices by physically touching different portions ofthe touchscreen. These touchscreens are usually on the front part of thedevice (the part of the device facing the user). In order for a user toinput commands to the devices using the touchscreen, the user has toplace a finger on the touchscreen at a desired position. This ends upobstructing the view of the content that is displayed at the desiredposition and its surroundings. It is nearly impossible to interact withthe touchscreen to input commands without at least partially obstructingview of the content presented on the touchscreen. This can interferewith the ability for the user to read content seamlessly and withoutinterruption on the screen. In cases where video content is being playedon the screen, the user can miss important portions of the content thatis being displayed when the user tries to manipulate playback of thecontent by physically interacting with the touchscreen.

Also, interactions with the touchscreen are usually performed with afree hand of the user. For example, if the user is holding the devicewith the right hand, the user may use the left hand to interact with thetouchscreen because it is too cumbersome and difficult to stretch theuser's fingers on the right hand to reach desired positions on thetouchscreen. Having the user operate the device with two hands makes itdifficult for the user to multi-task and interact physically with otherobjects. Specifically, the user may have a difficult time holding aremote control to interact with a television while, at the same time,navigating content on a touchscreen device.

Some typical approaches connect peripheral input devices, such as remotecontrollers and touchpads, to the device being controlled. Theseperipheral devices allow the user to control or provide input to thedevice being controlled without using the touchscreen. Such peripheraldevices, though, usually occupy additional space and consume otherresources of the device being controlled. In addition, such peripheraldevices either entirely disable the touchscreen of the device beingcontrolled or can introduce conflicts with the touchscreen of the devicebeing controlled, such as when an input is received by the touchscreenat the same time as an instruction is received from the peripheraldevice to operate the device being controlled. Also, such peripheraldevices need to be connected to an input port (e.g., a USB port) of thedevice being controlled leaving the input port unusable for otherpurposes, such as connecting a power cord to charge the battery of thedevice being controlled. While these typical approaches generally workwell for replacing how input is provided to the touchscreen devices withperipheral input devices, adding such peripheral devices introducesvarious complexities and is non-trivial. This is because such peripheraldevices need to be electrically compatible with the touchscreen devicebeing controlled, programmed or configured to communicate properly withthe operating system or software running on the touchscreen device beingcontrolled, and have a dedicated application running on the touchscreendevice for communicating and interpreting commands from the peripheraldevice.

The disclosed embodiments improve the efficiency and ease of using anelectronic touchscreen device by adding a touchpad component on the backof the touchscreen device that remotely and electrically controls thetouchscreen portion on the front of the touchscreen device. The touchpadcomponent can be placed on a back portion of the device facing away fromthe user, such as on the opposite side of the touchscreen facing theuser. This way, the user can operate the touchscreen device with onehand while holding the device. For example, the user can interact withthe touchpad component on the back of the device while viewing contenton the touchscreen on the front of the device. This avoids obstructingthe content being viewed while allowing the user to provide touch-basedinput to the device. As an example, the user can view a webpage on thefront of the device through the touchscreen and can swipe a fingerup/down on the touchpad on the back of the device to scroll the webpageup/down. Also, because the touchpad component electrically communicateswith the touchscreen on the front of the device, input resources, suchas a USB input port, do not need to be consumed. Additionally, becausethe input to the device still takes place ultimately through thetouchscreen, the operating system does not need special handling of thetouchpad component on the back and compatibility issues do not need tobe considered.

In some embodiments, the touchpad component activates a certaincombination of inputs on the touchscreen of the device, such asactivating a top position of the touchscreen and a bottom position ofthe touchscreen simultaneously. These combination of inputs may beunique to inputs received from the touchpad component on the back of thedevice which enable the touchscreen to distinguish between inputsreceived directly by a user physically touching the touchscreen andindirectly by the user physically touching the touchpad component on theback of the device. In certain cases, the touchpad component on the backof the device can be selectively disabled/enabled by toggling ormanipulating an analog or mechanical switch. Such a switch can beconfigured to disconnect logically or in an analog manner, theelectrical signals from the touchpad component on the back of the deviceto the touchscreen on the front of the device. In this way, when thetouchpad on the back of the device is disabled, the user cannotinadvertently or without intending to cause the touchscreen to becontrolled by the touchpad component on the back of the device when theuser is physically touching the touchpad component on the back of thedevice.

Networked Computing Environment

FIG. 1 is a block diagram showing an example messaging system 100 forexchanging data (e.g., messages and associated content) over a network.The messaging system 100 includes multiple instances of a client device102, each of which hosts a number of applications, including a messagingclient 104. Each messaging client 104 is communicatively coupled toother instances of the messaging client 104 and a messaging serversystem 108 via a network 106 (e.g., the Internet).

A messaging client 104 is able to communicate and exchange data withanother messaging client 104 and with the messaging server system 108via the network 106. The data exchanged between messaging client 104,and between a messaging client 104 and the messaging server system 108includes functions (e.g., commands to invoke functions) as well aspayload data (e.g., text, audio, video or other multimedia data).

The messaging server system 108 provides server-side functionality viathe network 106 to a particular messaging client 104. While certainfunctions of the messaging system 100 are described herein as beingperformed by either a messaging client 104 or by the messaging serversystem 108, the location of certain functionality either within themessaging client 104 or the messaging server system 108 may be a designchoice. For example, it may be technically preferable to initiallydeploy certain technology and functionality within the messaging serversystem 108 but to later migrate this technology and functionality to themessaging client 104 where a client device 102 has sufficient processingcapacity.

The messaging server system 108 supports various services and operationsthat are provided to the messaging client 104. Such operations includetransmitting data to, receiving data from, and processing data generatedby the messaging client 104. This data may include message content,client device information, geolocation information, media augmentationand overlays, message content persistence conditions, social networkinformation, and live event information, as examples. Data exchangeswithin the messaging system 100 are invoked and controlled throughfunctions available via user interfaces (UIs) of the messaging client104.

Turning now specifically to the messaging server system 108, anApplication Program Interface (API) server 110 is coupled to, andprovides a programmatic interface to, application servers 112. Theapplication servers 112 are communicatively coupled to a database server118, which facilitates access to a database 120 that stores dataassociated with messages processed by the application servers 112.Similarly, a web server 124 is coupled to the application servers 112,and provides web-based interfaces to the application servers 112. Tothis end, the web server 124 processes incoming network requests overthe Hypertext Transfer Protocol (HTTP) and several other relatedprotocols.

The Application Program Interface (API) server 110 receives andtransmits message data (e.g., commands and message payloads) between theclient device 102 and the application servers 112. Specifically, theApplication Program Interface (API) server 110 provides a set ofinterfaces (e.g., routines and protocols) that can be called or queriedby the messaging client 104 in order to invoke functionality of theapplication servers 112. The Application Program Interface (API) server110 exposes various functions supported by the application servers 112,including account registration, login functionality, the sending ofmessages, via the application servers 112, from a particular messagingclient 104 to another messaging client 104, the sending of media files(e.g., images or video) from a messaging client 104 to a messagingserver 114, and for possible access by another messaging client 104, thesettings of a collection of media data (e.g., story), the retrieval of alist of friends of a user of a client device 102, the retrieval of suchcollections, the retrieval of messages and content, the addition anddeletion of entities (e.g., friends) to an entity graph (e.g., a socialgraph), the location of friends within a social graph, and opening anapplication event (e.g., relating to the messaging client 104).

The application servers 112 host a number of server applications andsubsystems including, for example a messaging server 114, an imageprocessing server 116, and a social network server 122. The messagingserver 114 implements a number of message processing technologies andfunctions, particularly related to the aggregation and other processingof content (e.g., textual and multimedia content) included in messagesreceived from multiple instances of the messaging client 104. As will bedescribed in further detail, the text and media content from multiplesources may be aggregated into collections of content (e.g., calledstories or galleries). These collections are then made available to themessaging client 104. Other processor- and memory-intensive processingof data may also be performed server-side by the messaging server 114,in view of the hardware requirements for such processing.

The application servers 112 also include an image processing server 116that is dedicated to performing various image processing operations,typically with respect to images or video within the payload of amessage sent from or received at the messaging server 114.

The social network server 122 supports various social networkingfunctions and services and makes these functions and services availableto the messaging server 114. To this end, the social network server 122maintains and accesses an entity graph 306 (as shown in FIG. 3 ) withinthe database 120. Examples of functions and services supported by thesocial network server 122 include the identification of other users ofthe messaging system 100 with which a particular user has relationshipsor is “following,” and also the identification of other entities andinterests of a particular user.

System Architecture

FIG. 2 is a block diagram illustrating further details regarding themessaging system 100, according to some examples. Specifically, themessaging system 100 is shown to comprise the messaging client 104 andthe application servers 112. The messaging system 100 embodies a numberof subsystems, which are supported on the client side by the messagingclient 104 and on the sever side by the application servers 112. Thesesubsystems include, for example, an ephemeral timer system 202, acollection management system 204, an augmentation system 206, a mapsystem 208, and a game system 210.

The ephemeral timer system 202 is responsible for enforcing thetemporary or time-limited access to content by the messaging client 104and the messaging server 114. The ephemeral timer system 202incorporates a number of timers that, based on duration and displayparameters associated with a message, or collection of messages (e.g., astory), selectively enable access (e.g., for presentation and display)to messages and associated content via the messaging client 104. Furtherdetails regarding the operation of the ephemeral timer system 202 areprovided below.

The collection management system 204 is responsible for managing sets orcollections of media (e.g., collections of text, image video, and audiodata). A collection of content (e.g., messages, including images, video,text, and audio) may be organized into an “event gallery” or an “eventstory.” Such a collection may be made available for a specified timeperiod, such as the duration of an event to which the content relates.For example, content relating to a music concert may be made availableas a “story” for the duration of that music concert. The collectionmanagement system 204 may also be responsible for publishing an iconthat provides notification of the existence of a particular collectionto the user interface of the messaging client 104.

The collection management system 204 furthermore includes a curationinterface 212 that allows a collection manager to manage and curate aparticular collection of content. For example, the curation interface212 enables an event organizer to curate a collection of contentrelating to a specific event (e.g., delete inappropriate content orredundant messages). Additionally, the collection management system 204employs machine vision (or image recognition technology) and contentrules to automatically curate a content collection. In certain examples,compensation may be paid to a user for the inclusion of user-generatedcontent into a collection. In such cases, the collection managementsystem 204 operates to automatically make payments to such users for theuse of their content.

The augmentation system 206 provides various functions that enable auser to augment (e.g., annotate or otherwise modify or edit) mediacontent associated with a message. For example, the augmentation system206 provides functions related to the generation and publishing of mediaoverlays for messages processed by the messaging system 100. Theaugmentation system 206 operatively supplies a media overlay oraugmentation (e.g., an image filter) to the messaging client 104 basedon a geolocation of the client device 102. In another example, theaugmentation system 206 operatively supplies a media overlay to themessaging client 104 based on other information, such as social networkinformation of the user of the client device 102. A media overlay mayinclude audio and visual content and visual effects. Examples of audioand visual content include pictures, texts, logos, animations, and soundeffects. An example of a visual effect includes color overlaying. Theaudio and visual content or the visual effects can be applied to a mediacontent item (e.g., a photo) at the client device 102. For example, themedia overlay may include text or image that can be overlaid on top of aphotograph taken by the client device 102. In another example, the mediaoverlay includes an identification of a location overlay (e.g., Venicebeach), a name of a live event, or a name of a merchant overlay (e.g.,Beach Coffee House). In another example, the augmentation system 206uses the geolocation of the client device 102 to identify a mediaoverlay that includes the name of a merchant at the geolocation of theclient device 102. The media overlay may include other indiciaassociated with the merchant. The media overlays may be stored in thedatabase 120 and accessed through the database server 118.

In some examples, the augmentation system 206 provides a user-basedpublication platform that enables users to select a geolocation on a mapand upload content associated with the selected geolocation. The usermay also specify circumstances under which a particular media overlayshould be offered to other users. The augmentation system 206 generatesa media overlay that includes the uploaded content and associates theuploaded content with the selected geolocation.

In other examples, the augmentation system 206 provides a merchant-basedpublication platform that enables merchants to select a particular mediaoverlay associated with a geolocation via a bidding process. Forexample, the augmentation system 206 associates the media overlay of thehighest bidding merchant with a corresponding geolocation for apredefined amount of time.

The map system 208 provides various geographic location functions, andsupports the presentation of map-based media content and messages by themessaging client 104. For example, the map system 208 enables thedisplay of user icons or avatars (e.g., stored in profile data 308) on amap to indicate a current or past location of “friends” of a user, aswell as media content (e.g., collections of messages includingphotographs and videos) generated by such friends, within the context ofa map. For example, a message posted by a user to the messaging system100 from a specific geographic location may be displayed within thecontext of a map at that particular location to “friends” of a specificuser on a map interface of the messaging client 104. A user canfurthermore share his or her location and status information (e.g.,using an appropriate status avatar) with other users of the messagingsystem 100 via the messaging client 104, with this location and statusinformation being similarly displayed within the context of a mapinterface of the messaging client 104 to selected users.

The game system 210 provides various gaming functions within the contextof the messaging client 104. The messaging client 104 provides a gameinterface providing a list of available games that can be launched by auser within the context of the messaging client 104, and played withother users of the messaging system 100. The messaging system 100further enables a particular user to invite other users to participatein the play of a specific game, by issuing invitations to such otherusers from the messaging client 104. The messaging client 104 alsosupports both voice and text messaging (e.g., chats) within the contextof gameplay, provides a leaderboard for the games, and also supports theprovision of in-game rewards (e.g., coins and items).

The messaging client 104 receives inputs from a touchscreen of clientdevice 102. The messaging client 104 determines whether the inputs fromthe touchscreen of the client device 102 correspond to interactions by auser with a touchpad component on the back of the device 102. Forexample, when multiple positions of the touchscreen are activatedsimultaneously and that correspond to a particular combination ofsimultaneously activated positions, the messaging client 104 determinesthat the touchscreen received inputs from the touchpad component on theback of the client device 102 rather than by direct physical touch tothe touchscreen. In some embodiments, a user may toggle an on-screenoption that is displayed by the operating system or messaging client 104to instruct the operating system or messaging client 104 to interpretinputs on the touchscreen as being received from interactions with thetouchpad on the back of the device 102.

When the messaging client 104 or operating system detects (by directuser instructions or by a unique activation of a combination ofpositions of the touchscreen of the client device 102) that a user isproviding inputs to the touchscreen indirectly by interacting with thetouchpad on the back of the client device 102, the messaging client 104or operating system interprets the combination of inputs on thetouchscreen to generate a command to control operation of the clientdevice 102. For example, the messaging client 104 determines that onecombination of the inputs on the touchscreen that is activated by theuser interacting with the touchpad component on the back of the clientdevice 102 corresponds to a scroll down operation. In such cases, themessaging client 104 scrolls the page being displayed on the touchscreendown. As another example, the messaging client 104 determines that asecond combination of the inputs on the touchscreen that is activated bythe user interacting with the touchpad component on the back of theclient device 102 corresponds to a select operation. In such cases, themessaging client 104 instructs an application, such as a game, that ispresenting the content on the touchscreen to perform a select operation.

Data Architecture

FIG. 3 is a schematic diagram illustrating data structures 300, whichmay be stored in the database 120 of the messaging server system 108,according to certain examples. While the content of the database 120 isshown to comprise a number of tables, it will be appreciated that thedata could be stored in other types of data structures (e.g., as anobject-oriented database).

The database 120 includes message data stored within a message table302. This message data includes, for any one particular message, atleast message sender data, message recipient (or receiver) data, and apayload. Further details regarding information that may be included in amessage, and included within the message data stored in the messagetable 302, is described below with reference to FIG. 4 .

An entity table 304 stores entity data, and is linked (e.g.,referentially) to an entity graph 306 and profile data 308. Entities forwhich records are maintained within the entity table 304 may includeindividuals, corporate entities, organizations, objects, places, events,and so forth. Regardless of entity type, any entity regarding which themessaging server system 108 stores data may be a recognized entity. Eachentity is provided with a unique identifier, as well as an entity typeidentifier (not shown).

The entity graph 306 stores information regarding relationships andassociations between entities. Such relationships may be social,professional (e.g., work at a common corporation or organization)interested-based or activity-based, merely for example.

The profile data 308 stores multiple types of profile data about aparticular entity. The profile data 308 may be selectively used andpresented to other users of the messaging system 100, based on privacysettings specified by a particular entity. Where the entity is anindividual, the profile data 308 includes, for example, a user name,telephone number, address, settings (e.g., notification and privacysettings), as well as a user-selected avatar representation (orcollection of such avatar representations). A particular user may thenselectively include one or more of these avatar representations withinthe content of messages communicated via the messaging system 100, andon map interfaces displayed by messaging clients 104 to other users. Thecollection of avatar representations may include “status avatars,” whichpresent a graphical representation of a status or activity that the usermay select to communicate at a particular time.

Where the entity is a group, the profile data 308 for the group maysimilarly include one or more avatar representations associated with thegroup, in addition to the group name, members, and various settings(e.g., notifications) for the relevant group.

The database 120 also stores augmentation data, such as overlays orfilters, in an augmentation table 310. The augmentation data isassociated with and applied to videos (for which data is stored in avideo table 314) and images (for which data is stored in an image table316).

Filters, in one example, are overlays that are displayed as overlaid onan image or video during presentation to a recipient user. Filters maybe of various types, including user-selected filters from a set offilters presented to a sending user by the messaging client 104 when thesending user is composing a message. Other types of filters includegeolocation filters (also known as geo-filters), which may be presentedto a sending user based on geographic location. For example, geolocationfilters specific to a neighborhood or special location may be presentedwithin a user interface by the messaging client 104, based ongeolocation information determined by a Global Positioning System (GPS)unit of the client device 102.

Another type of filter is a data filter, which may be selectivelypresented to a sending user by the messaging client 104, based on otherinputs or information gathered by the client device 102 during themessage creation process. Examples of data filters include currenttemperature at a specific location, a current speed at which a sendinguser is traveling, battery life for a client device 102, or the currenttime.

Other augmentation data that may be stored within the image table 316includes augmented reality content items (e.g., corresponding toapplying Lenses or augmented reality experiences). An augmented realitycontent item may be a real-time special effect and sound that may beadded to an image or a video.

As described above, augmentation data includes augmented reality contentitems, overlays, image transformations, AR images, and similar termsthat refer to modifications that may be applied to image data (e.g.,videos or images). This includes real-time modifications, which modifyan image as it is captured using device sensors (e.g., one or multiplecameras) of a client device 102 and then displayed on a screen of theclient device 102 with the modifications. This also includesmodifications to stored content, such as video clips in a gallery thatmay be modified. For example, in a client device 102 with access tomultiple augmented reality content items, a user can use a single videoclip with multiple augmented reality content items to see how thedifferent augmented reality content items will modify the stored clip.For example, multiple augmented reality content items that applydifferent pseudorandom movement models can be applied to the samecontent by selecting different augmented reality content items for thecontent. Similarly, real-time video capture may be used with anillustrated modification to show how video images currently beingcaptured by sensors of a client device 102 would modify the captureddata. Such data may simply be displayed on the screen and not stored inmemory, or the content captured by the device sensors may be recordedand stored in memory with or without the modifications (or both). Insome systems, a preview feature can show how different augmented realitycontent items will look within different windows in a display at thesame time. This can, for example, enable multiple windows with differentpseudorandom animations to be viewed on a display at the same time.

Data and various systems using augmented reality content items or othersuch transform systems to modify content using this data can thusinvolve detection of objects (e.g., faces, hands, bodies, cats, dogs,surfaces, objects, etc.), tracking of such objects as they leave, enter,and move around the field of view in video frames, and the modificationor transformation of such objects as they are tracked. In variousembodiments, different methods for achieving such transformations may beused. Some examples may involve generating a three-dimensional meshmodel of the object or objects, and using transformations and animatedtextures of the model within the video to achieve the transformation. Inother examples, tracking of points on an object may be used to place animage or texture (which may be two dimensional or three dimensional) atthe tracked position. In still further examples, neural network analysisof video frames may be used to place images, models, or textures incontent (e.g., images or frames of video). Augmented reality contentitems thus refer both to the images, models, and textures used to createtransformations in content, as well as to additional modeling andanalysis information needed to achieve such transformations with objectdetection, tracking, and placement.

Real-time video processing can be performed with any kind of video data(e.g., video streams, video files, etc.) saved in a memory of acomputerized system of any kind. For example, a user can load videofiles and save them in a memory of a device, or can generate a videostream using sensors of the device. Additionally, any objects can beprocessed using a computer animation model, such as a human's face andparts of a human body, animals, or non-living things such as chairs,cars, or other objects.

In some examples, when a particular modification is selected along withcontent to be transformed, elements to be transformed are identified bythe computing device, and then detected and tracked if they are presentin the frames of the video. The elements of the object are modifiedaccording to the request for modification, thus transforming the framesof the video stream. Transformation of frames of a video stream can beperformed by different methods for different kinds of transformation.For example, for transformations of frames mostly referring to changingforms of objects' elements, characteristic points for each element of anobject are calculated (e.g., using an Active Shape Model (ASM) or otherknown methods). Then, a mesh based on the characteristic points isgenerated for each of the at least one element of the object. This meshis used in the following stage of tracking the elements of the object inthe video stream. In the process of tracking, the mentioned mesh foreach element is aligned with a position of each element. Then,additional points are generated on the mesh. A set of first points isgenerated for each element based on a request for modification, and aset of second points is generated for each element based on the set offirst points and the request for modification. Then, the frames of thevideo stream can be transformed by modifying the elements of the objecton the basis of the sets of first and second points and the mesh. Insuch method, a background of the modified object can be changed ordistorted as well by tracking and modifying the background.

In some examples, transformations changing some areas of an object usingits elements can be performed by calculating characteristic points foreach element of an object and generating a mesh based on the calculatedcharacteristic points. Points are generated on the mesh, and thenvarious areas based on the points are generated. The elements of theobject are then tracked by aligning the area for each element with aposition for each of the at least one element, and properties of theareas can be modified based on the request for modification, thustransforming the frames of the video stream. Depending on the specificrequest for modification, properties of the mentioned areas can betransformed in different ways. Such modifications may involve changingcolor of areas; removing at least some part of areas from the frames ofthe video stream; including one or more new objects into areas which arebased on a request for modification; and modifying or distorting theelements of an area or object. In various embodiments, any combinationof such modifications or other similar modifications may be used. Forcertain models to be animated, some characteristic points can beselected as control points to be used in determining the entirestate-space of options for the model animation.

In some examples of a computer animation model to transform image datausing face detection, the face is detected on an image with use of aspecific face detection algorithm (e.g., Viola-Jones). Then, an ActiveShape Model (ASM) algorithm is applied to the face region of an image todetect facial feature reference points.

In other examples, other methods and algorithms suitable for facedetection can be used. For example, in some embodiments, features arelocated using a landmark, which represents a distinguishable pointpresent in most of the images under consideration. For facial landmarks,for example, the location of the left eye pupil may be used. If aninitial landmark is not identifiable (e.g., if a person has aneyepatch), secondary landmarks may be used. Such landmark identificationprocedures may be used for any such objects. In some examples, a set oflandmarks forms a shape. Shapes can be represented as vectors using thecoordinates of the points in the shape. One shape is aligned to anotherwith a similarity transform (allowing translation, scaling, androtation) that minimizes the average Euclidean distance between shapepoints. The mean shape is the mean of the aligned training shapes.

In some examples, a search for landmarks from the mean shape aligned tothe position and size of the face determined by a global face detectoris started. Such a search then repeats the steps of suggesting atentative shape by adjusting the locations of shape points by templatematching of the image texture around each point and then conforming thetentative shape to a global shape model until convergence occurs. Insome systems, individual template matches are unreliable, and the shapemodel pools the results of the weak template matches to form a strongeroverall classifier. The entire search is repeated at each level in animage pyramid, from coarse to fine resolution.

A transformation system can capture an image or video stream on a clientdevice (e.g., the client device 102) and perform complex imagemanipulations locally on the client device 102 while maintaining asuitable user experience, computation time, and power consumption. Thecomplex image manipulations may include size and shape changes, emotiontransfers (e.g., changing a face from a frown to a smile), statetransfers (e.g., aging a subject, reducing apparent age, changinggender), style transfers, graphical element application, and any othersuitable image or video manipulation implemented by a convolutionalneural network that has been configured to execute efficiently on theclient device 102.

In some examples, a computer animation model to transform image data canbe used by a system where a user may capture an image or video stream ofthe user (e.g., a selfie) using a client device 102 having a neuralnetwork operating as part of a messaging client 104 operating on theclient device 102. The transformation system operating within themessaging client 104 determines the presence of a face within the imageor video stream and provides modification icons associated with acomputer animation model to transform image data, or the computeranimation model can be present as associated with an interface describedherein. The modification icons include changes that may be the basis formodifying the user's face within the image or video stream as part ofthe modification operation. Once a modification icon is selected, thetransformation system initiates a process to convert the image of theuser to reflect the selected modification icon (e.g., generate a smilingface on the user). A modified image or video stream may be presented ina graphical user interface displayed on the client device 102 as soon asthe image or video stream is captured, and a specified modification isselected. The transformation system may implement a complexconvolutional neural network on a portion of the image or video streamto generate and apply the selected modification. That is, the user maycapture the image or video stream and be presented with a modifiedresult in real-time or near real-time once a modification icon has beenselected. Further, the modification may be persistent while the videostream is being captured, and the selected modification icon remainstoggled. Machine-taught neural networks may be used to enable suchmodifications.

The graphical user interface, presenting the modification performed bythe transformation system, may supply the user with additionalinteraction options. Such options may be based on the interface used toinitiate the content capture and selection of a particular computeranimation model (e.g., initiation from a content creator userinterface). In various embodiments, a modification may be persistentafter an initial selection of a modification icon. The user may togglethe modification on or off by tapping or otherwise selecting the facebeing modified by the transformation system and store it for laterviewing or browse to other areas of the imaging application. Wheremultiple faces are modified by the transformation system, the user maytoggle the modification on or off globally by tapping or selecting asingle face modified and displayed within a graphical user interface. Insome embodiments, individual faces, among a group of multiple faces, maybe individually modified, or such modifications may be individuallytoggled by tapping or selecting the individual face or a series ofindividual faces displayed within the graphical user interface.

A story table 312 stores data regarding collections of messages andassociated image, video, or audio data, which are compiled into acollection (e.g., a story or a gallery). The creation of a particularcollection may be initiated by a particular user (e.g., each user forwhich a record is maintained in the entity table 304). A user may createa “personal story” in the form of a collection of content that has beencreated and sent/broadcast by that user. To this end, the user interfaceof the messaging client 104 may include an icon that is user-selectableto enable a sending user to add specific content to his or her personalstory.

A collection may also constitute a “live story,” which is a collectionof content from multiple users that is created manually, automatically,or using a combination of manual and automatic techniques. For example,a “live story” may constitute a curated stream of user-submitted contentfrom various locations and events. Users whose client devices 102 havelocation services enabled and are at a common location event at aparticular time may, for example, be presented with an option, via auser interface of the messaging client 104, to contribute content to aparticular live story. The live story may be identified to the user bythe messaging client 104, based on his or her location. The end resultis a “live story” told from a community perspective.

A further type of content collection is known as a “location story,”which enables a user whose client device 102 is located within aspecific geographic location (e.g., on a college or university campus)to contribute to a particular collection. In some examples, acontribution to a location story may require a second degree ofauthentication to verify that the end user belongs to a specificorganization or other entity (e.g., is a student on the universitycampus).

As mentioned above, the video table 314 stores video data that, in oneexample, is associated with messages for which records are maintainedwithin the message table 302. Similarly, the image table 316 storesimage data associated with messages for which message data is stored inthe entity table 304. The entity table 304 may associate variousaugmentations from the augmentation table 310 with various images andvideos stored in the image table 316 and the video table 314.

The trackpad conversion table 318 maps different combinations ofpositions of the touchscreen being activated to different operations.Specifically, the trackpad conversion table 318 maps combinations ofpositions of the touchscreen that are activated when a user physicallytouches a touchpad on the back of the client device 102 to variousoperations. For example, a first combination of positions of thetouchscreen, such as a first position at the top of the touchscreensimultaneously activated with a first position at the bottom of thetouchscreen, corresponds to a select operation. For example, a secondcombination of positions of the touchscreen, such as a second positionat the top of the touchscreen simultaneously activated with a secondposition at the bottom of the touchscreen, corresponds to a scrolloperation. Trackpad and touchpad are used interchangeably throughoutthis disclosure and may be understood to have the same functionality.

In some embodiments, the trackpad conversion table 318 may differ fordifferent applications. For example, the trackpad conversion table 318maps a first set of combinations of positions of the touchscreen beingactivated to a respective first set of operations when a user interfaceof a first application (e.g., a gaming application) is currently beingpresented on the touchscreen of the client device 102. In such cases, afirst combination of positions of the touchscreen, such as a firstposition at the top of the touchscreen simultaneously activated with afirst position at the bottom of the touchscreen, corresponds to a selectoperation. As another example, the trackpad conversion table 318 maps asecond set of combinations of positions of the touchscreen beingactivated to a respective second set of operations when a user interfaceof a second application (e.g., a web-browsing application or messagingclient 104) is currently being presented on the touchscreen of theclient device 102. In such cases, the first combination of positions ofthe touchscreen, such as the first position at the top of thetouchscreen simultaneously activated with the first position at thebottom of the touchscreen, corresponds to a scroll operation.

Data Communications Architecture

FIG. 4 is a schematic diagram illustrating a structure of a message 400,according to some examples, generated by a messaging client 104 forcommunication to a further messaging client 104 or the messaging server114. The content of a particular message 400 is used to populate themessage table 302 stored within the database 120, accessible by themessaging server 114. Similarly, the content of a message 400 is storedin memory as “in-transit” or “in-flight” data of the client device 102or the application servers 112. A message 400 is shown to include thefollowing example components:

-   -   message identifier 402: a unique identifier that identifies the        message 400.    -   message text payload 404: text, to be generated by a user via a        user interface of the client device 102, and that is included in        the message 400.    -   message image payload 406: image data, captured by a camera        component of a client device 102 or retrieved from a memory        component of a client device 102, and that is included in the        message 400. Image data for a sent or received message 400 may        be stored in the image table 316.    -   message video payload 408: video data, captured by a camera        component or retrieved from a memory component of the client        device 102, and that is included in the message 400. Video data        for a sent or received message 400 may be stored in the video        table 314.    -   message audio payload 410: audio data, captured by a microphone        or retrieved from a memory component of the client device 102,        and that is included in the message 400.    -   message augmentation data 412: augmentation data (e.g., filters,        stickers, or other annotations or enhancements) that represents        augmentations to be applied to message image payload 406,        message video payload 408, or message audio payload 410 of the        message 400. Augmentation data for a sent or received message        400 may be stored in the augmentation table 310.    -   message duration parameter 414: parameter value indicating, in        seconds, the amount of time for which content of the message        (e.g., the message image payload 406, message video payload 408,        message audio payload 410) is to be presented or made accessible        to a user via the messaging client 104.    -   message geolocation parameter 416: geolocation data (e.g.,        latitudinal and longitudinal coordinates) associated with the        content payload of the message. Multiple message geolocation        parameter 416 values may be included in the payload, each of        these parameter values being associated with respect to content        items included in the content (e.g., a specific image within the        message image payload 406, or a specific video in the message        video payload 408).    -   message story identifier 418: identifier values identifying one        or more content collections (e.g., “stories” identified in the        story table 312) with which a particular content item in the        message image payload 406 of the message 400 is associated. For        example, multiple images within the message image payload 406        may each be associated with multiple content collections using        identifier values.    -   message tag 420: each message 400 may be tagged with multiple        tags, each of which is indicative of the subject matter of        content included in the message payload. For example, where a        particular image included in the message image payload 406        depicts an animal (e.g., a lion), a tag value may be included        within the message tag 420 that is indicative of the relevant        animal. Tag values may be generated manually, based on user        input, or may be automatically generated using, for example,        image recognition.    -   message sender identifier 422: an identifier (e.g., a messaging        system identifier, email address, or device identifier)        indicative of a user of the client device 102 on which the        message 400 was generated and from which the message 400 was        sent.    -   message receiver identifier 424: an identifier (e.g., a        messaging system identifier, email address, or device        identifier) indicative of a user of the client device 102 to        which the message 400 is addressed.

The contents (e.g., values) of the various components of message 400 maybe pointers to locations in tables within which content data values arestored. For example, an image value in the message image payload 406 maybe a pointer to (or address of) a location within an image table 316.Similarly, values within the message video payload 408 may point to datastored within a video table 314, values stored within the messageaugmentation data 412 may point to data stored in an augmentation table310, values stored within the message story identifier 418 may point todata stored in a story table 312, and values stored within the messagesender identifier 422 and the message receiver identifier 424 may pointto user records stored within an entity table 304.

FIG. 5 is a diagrammatic representation 500 of remote interaction with atouchscreen, in accordance with some examples. As shown inrepresentation 500, a touchscreen device 510 is displaying a set ofcontent on the screen, such as a keypad on a front of the device, suchas client device 102. The touchscreen device 510 includes a back portion520 which faces the opposite direction from the touchscreen on the frontof the device. For example, a surface normal of the front of thetouchscreen device 510 extends from the front of the device in a firstdirection and a surface normal of the back of the touchscreen device 510extends from the back of the touchscreen device 510 in a seconddirection opposite the first direction. A user holds the touchscreendevice 510 so that the front of the device is visible to and faces theuser while the back of the device faces away from the user.

The touchscreen of the touchscreen device 510 includes a two-dimensionalarray or matrix of capacitors placed at individual positions on theentire visible space of the touchscreen. The touchscreen device 510polls each capacitor in a suitable manner to detect change to acapacitance of one or more capacitors. As an example, when a user makesphysical contact with a particular region of the touchscreen device 510that includes one or more capacitors, the capacitance of the capacitorswhich are touched by the physical contact changes. The touchscreendevice 510 detects changes to the capacitance of these capacitors whichthe user physically touches and, in response, determines that the regionoccupied by these capacitors was touched by the user. The touchscreendevice 510 communicates the x and y coordinates of the region to asoftware application which then performs a particular operation orfunction. For example, if the number 6 of a keypad was displayed by thesoftware application at the region which the touchscreen device 510detected change to the capacitance, the software application maydetermine that the number 6 was selected. The software applicationperforms a function or operation, such as adding the number 6 to a textstring or calculator.

Another way to activate or change the capacitance value of thecapacitors of the touchscreen is remotely without making physicalcontact between a user's finger and the designated region of thetouchscreen that includes the capacitors. For example, a conductive wireor material is attached to the designated region 512 which includes thetarget capacitors. The conductive wire 514 extends a particular length(e.g., 20 centimeters) and has an end 516 which is also conductive. Whenthe user physically touches the end 516 with the user's finger, thecharge from the user's finger discharges or changes the capacitance ofthe capacitors in the designated region 512. This results in thetouchscreen detecting touch of the capacitors in the designated region512 without the user physically making contact with the capacitors inthe designated region 512. In this way, the user can remotely activatedifferent regions of the touchscreen of the touchscreen device 510without actually touching capacitors in a given one of the regions.

According to the disclosed embodiments, a conductive material 530 isplaced as a layer on top of one or more regions of the touchscreen ofthe touchscreen device 510. This conductive material 530 is electricallyconnected to respective regions of a touchpad on the back portion 520 ofthe touchscreen device 510. When a user makes physical contact with agiven region of the touchpad on the back portion 520, an electricalsignal is transmitted to the region of the touchscreen connected to thegiven region. This electrical signal activates or changes thecapacitance of the capacitors associated with the region of thetouchscreen and results in a particular operation of the softwareapplication to be performed.

In some embodiments, the conductive material 530 is placed over anentire portion or one or more segments of the touchscreen device 510.The conductive material 530 may be a conductive transparent materialthat comprises indium tin oxide (ITO). The conductive material may bepartially transparent. The conductive material 530 may have a one-to-onecorrespondence between each capacitor of the touchscreen on the frontportion of the touchscreen device 510 with each capacitor or touchsensor of the touchpad on the back portion 520 of the touchscreen device510. In such cases, the conductive material 530 covers a two-dimensionalarray or grid of capacitors on the touchscreen on the front of thetouchscreen device 510.

In some embodiments, the conductive material 530 is placed over a smallregion on the left, right, top, or bottom on the front of thetouchscreen device 510. The conductive material 530, in such cases, onlycovers a one-dimensional array of capacitors of the touchscreen on thefront portion of the touchscreen device 510. Namely, the conductivematerial 530 includes a one-dimensional array of conductive elementsthat are physically positioned over the one-dimensional array ofcapacitors. The conductive elements deliver an electric charge to therespective capacitors of the one-dimensional array of capacitors when acorresponding touch sensor of a trackpad on the back of the clientdevice 102 is physically touched by a user. In some implementations, thetrackpad on the back portion 520 of the touchscreen device 510 is alsoone-dimensional and has a one-to-one correspondence with theone-dimensional array of capacitors of the touchscreen on the front ofthe touchscreen device 510 via the conductive elements of the conductivematerial 530 placed over the one-dimensional array of capacitors of thetouchscreen.

FIG. 6 is a diagrammatic representation 600 of an embodiment of theclient device 102 with a trackpad on the back of the client device, inaccordance with some examples. As shown in representation 600, on theleft is the front portion of the client device 102 that includes thetouchscreen 640 covered, at least in party by the conductive material643, and on the right is the back portion of the client device 102 thatincludes the trackpad 642. A one-to-one correspondence is shown betweenthe one-dimensional array of capacitors 610 of the touchscreen on thefront of the client device 102 via the conductive elements of theconductive material 643 and the one-dimensional array of touch sensors620 on the back of the client device 102. An electrical connection 630,such as using a metal or conductive wire 514, is formed between eachtouch sensor of the touchpad on the back of the client device 102 and arespective capacitor in the one-dimensional array of capacitors 610 onthe front of the device via the conductive elements of the conductivematerial 643. In such cases, when a user physically touches a firsttouch sensor 622 on the back of the client device 102, an electricalsignal is sent to the electrically coupled corresponding capacitor 612of the touchscreen 640 on the front of the client device 102 via thecorresponding conductive element of the conductive material 643 thatoverlays the corresponding capacitor. The application running on theclient device 102 that displays content on the touchscreen can performan operation associated with receiving a touch input of the capacitor612. In one example, a user can swipe a finger down a column of sensorsof the one-dimensional array of touch sensors 620 on the back of theclient device 102 which respectively activates respective capacitors onthe touchscreen 640 on the front of the device. This gesture isinterpreted as a swipe down operation which may cause the applicationrunning on the client device 102 to scroll down or up content beingdisplayed on the touchscreen 640.

In some implementations, the trackpad 642 on the back portion 520 of thetouchscreen device 510 is two-dimensional and has a many-to-onecorrespondence with the one-dimensional array of capacitors of thetouchscreen on the front of the touchscreen device 510. In suchcircumstances, a first set of multiple touch sensors on the trackpad 642on the back portion 520 is connected electrically to a first capacitoron the front portion of the touchscreen device 510 and a second set ofmultiple touch sensors on the trackpad 642 on the back portion 520 isconnected electrically to a second capacitor on the front portion of thetouchscreen device 510.

FIG. 7 is a diagrammatic representation 700 of an embodiment of theclient device 102 with a trackpad 742 on the back of the client device,in accordance with some examples. As shown in representation 700, on theleft is the front portion of the client device 102 that includes thetouchscreen 740 covered, at least in part, by the conductive material643, and on the right is the back portion 520 of the client device 102that includes the trackpad 742. A many-to-one correspondence is shownbetween the one-dimensional array of capacitors 710 of the touchscreenon the front of the client device 102 and the two-dimensional array ormatrix of touch sensors 720 on the back of the client device 102 via theconductive elements of the conductive material 643. A first set ofelectrical connections 732, such as using one or more metal orconductive wires 514, is formed between a first set of touch sensors ofthe touchpad on the back of the client device 102 and a respectivecapacitor 612 in a first portion 712 (e.g., a top portion) of theone-dimensional array of capacitors 710 on the front of the device viathe conductive material 643. A second set of electrical connections 734,such as using one or more metal or conductive wires 514, is formedbetween a second set of touch sensors of the touchpad on the back of theclient device 102 and a respective capacitor 612 in a second portion 714(e.g., bottom portion) of the one-dimensional array of capacitors 710 onthe front of the device via the conductive material 643.

In such cases, when a user physically touches a first collection ofsensors 722 on the back of the client device 102, an electrical signalis sent to the electrically coupled corresponding capacitors 718 and 716of the touchscreen on the front of the client device 102 through or viathe conductive material 643 that is placed on top of the capacitors 718and 716. For example, while the user touches four sensors on thetouchpad on the back of the client device 102, only two capacitors(e.g., less capacitors than the number of sensors that are touched), onefrom the first portion 712 and one from the second portion 714, of thecapacitors on the front of the client device 102 are discharged oractivated or have their charges changed. The application running on theclient device 102 that displays content on the touchscreen 740 canperform an operation associated with receiving a touch input of thecombination of capacitors 718 and 716.

In some embodiments, a switch 740, such as a mechanical, digital oranalog switch is provided on the client device 102. The switch 740 maybe placed on the front portion of the client device 102, on the backportion of the client device 102, or along one of the edges or sides ofthe client device 102. The switch 740 may be a push button or togglebutton. The switch 740 may operatively disconnect the electricalcoupling between the trackpad on the back of the client device 102 fromthe conductive layer on the front of the client device 102. This allowsa user to selectively activate or deactivate controlling the touchscreen740 of the client device 102 on the front of the client device 102 usingthe touchpad on the back of the device. For example, when the switch 740is in the engaged or active state, the electrical connections are formedbetween the trackpad 742 on the back of the client device 102 and theconductive layer 643 on the front of the client device 102. In suchcases, when the user touches a given one or more touch sensors 720 ofthe trackpad 742 on the back of the device, a corresponding one or morecapacitors of the touchscreen 740 on the front of the client device 102are discharged, activated or have their charges change. This is due toan electrical signal that is allowed to be transmitted from the touchsensors 720 that are touched to the corresponding conductive elements ofthe conductive material 643 which then discharges or changes the chargeof the capacitor 612 overlaid by the conductive element. For example,when the switch 740 is in the disengaged or inactive state, theelectrical connections are removed or disconnected between the trackpad742 on the back of the client device 102 and the conductive layer 643 onthe front of the client device 102. In such cases, when the user touchesa given one or more touch sensors 720 of the trackpad 742 on the back ofthe device 102, a corresponding one or more capacitors of thetouchscreen 740 on the front of the client device 102 are not impactedor not discharged.

In some cases, the switch 740 includes A input, B output, a power inputand a control signal input. The A input receives respective signals fromtouch sensors 720 of the touchpad on the back of the client device 102and delivers the respective signals to a respective B output to acorresponding conductive element of the conductive layer 643 on thefront of the client device 102. The control signal input enables ordisables the delivery of the electrical signal from the A input to the Boutput. When the switch 740 is in the disabled state, the control signalprevents the A input from delivering signals to the B output. When theswitch 740 is in the enabled, state, the A input delivers signals to theB output based on which touch sensors 720 of the trackpad 742 on theback of the client device 102 are physically touched by a user.

FIG. 8 is a diagrammatic representation 800 of an embodiment of theclient device 102 with a trackpad on the back of the client device, inaccordance with some examples. Representation 800 shows a combination ofthe embodiments shown in FIGS. 6 and 7 . The representation 800 shown inFIG. 8 may be suitable for a gaming application. The trackpad on theback of the client device 102 includes a first pair of controllers 820and 822 that each includes a respective set of touch sensors 720. Thesetouch sensors 720 are coupled electrically directly to respectiveconductive elements of the conductive material 810 and 812 in aone-to-one correspondence, similar to that shown in FIG. 6 . Theconductive elements activate respective touchscreen capacitors atrespective positions. The trackpad on the back of the client device 102includes a two-dimensional grid 830 of touch sensors 720. These sensorsare coupled in a many-to-one arrangement (similar to that shown in FIG.7 ), such that a particular group of touch sensors 720 is coupledelectrically directly to one particular conductive element of theconductive material. The two-dimensional grid 830 of touch sensors isconfigured to simultaneously activate a given pair of touchscreencapacitors at different positions (e.g., at the top and at the bottom ofthe client device 102) when a group of touch sensors 720 are physicallytouched by a user.

FIG. 9 is a diagrammatic representation 900 of an embodiment of theclient device 102 with a trackpad on the back of the client device, inaccordance with some examples. Representation 900 shows anotherimplementation of the embodiment shown in FIG. 6 . The representation900 shown in FIG. 9 may be suitable for a music application. Forexample, the touch sensors 720 of the touchpad on the back of the clientdevice 102 are arranged similar to the way in which keys of a musicalinstrument are arranged (e.g., piano keys). The touchpad can have aphysical appearance to resemble the keys of the musical instrument. Eachtouch sensor of a first portion 920 of the touchpad can be directlyelectrically coupled to in a one-to-one correspondence to acorresponding first portion 910 of the conductive material 810 on thefront of the client device 102 that contains a first set of conductiveelements. Each conductive element of the first set of conductiveelements is configured to deliver an electrical signal to a respectivetouchscreen capacitor 612 at a particular position. Each touch sensor ofa second portion 922 of the touchpad can be directly electricallycoupled to in a one-to-one correspondence to a corresponding secondportion 912 of the conductive material 810 on the front of the clientdevice 102 that contains a second set of conductive elements. Eachconductive element of the second set of conductive elements isconfigured to deliver an electrical signal to a respective touchscreencapacitor 612 at a particular position. Although piano keys are shownand described any other suitable musical instrument keys and arrangementof such keys can be similarly provided by the touchpad on the back ofthe client device 102, such as a harp, a trumpet, and so forth.

As discussed above, the trackpad on the back of the client device 102can take many different patterns. Various patterns are discussed abovein connection with FIGS. 6-9 . The pattern for a particular trackpad onthe back of the client device 102 can be changed manually by a userchanging a physical tangible module that includes the conductivematerial 810 that overlays the touchscreen on the front of the deviceand that includes the trackpad on the back of the client device 102. Theuser can purchase or access various modules that each contain adifferent pattern for the trackpad on the back of the client device 102and can swap out the modules by inserting the client device 102 into themodule that is desired in the form of a sleeve or cover. The pattern ofthe touch sensors 720 of the touchpad or trackpad may include a squaregrid, a circular grid or a plurality of individual shapes or differentshapes.

In some implementations, the conductive material 810 that overlays thetouchscreen on the front of the device and that includes the trackpad onthe back of the client device 102 can have an electronically selectedpattern of conductive elements on the front of the device and touchsensors 720 on the trackpad on the back of the client device 102. A usercan select a particular pattern by setting a particular physical switch740 or by sending a communication to the module that contains theconductive material 810 and trackpad on the back of the client device102. For example, the user can communicate with the module that containsthe conductive material 810 and trackpad via wireless communication,such as Bluetooth or WiFi. In some cases, the client device 102 cantransmit a communication electronically by wireless to the module thatcontains the conductive material 810 and trackpad with instructions onthe type of pattern for the conductive elements and the touch sensors onthe trackpad. In one instance, the trackpad and the conductive elementsof the conductive material 810 can take the form shown in FIG. 7 and inresponse to receiving a communication from an external device, such asclient device 102, the module can change to take a different form, suchas the form shown in FIG. 8 .

FIG. 10 is a flowchart illustrating example operations of the trackpadon back of device system in performing process 1000, according toexample embodiments. The process 1000 may be embodied incomputer-readable instructions for execution by one or more processorssuch that the operations of the process 1000 may be performed in part orin whole by the functional components of the client device 102;accordingly, the process 1000 is described below by way of example withreference thereto. However, in other embodiments at least some of theoperations of the process 1000 may be deployed on various other hardwareconfigurations. The operations in the process 1000 can be performed inany order, in parallel, or may be entirely skipped and omitted

At operation 1001, the client device 102, displaying a graphical userinterface on a touch-sensitive display screen of a front portion of theclient device, detects physical touch of a touch-sensitive component ona back portion 520 of a client device. For example, as shown inrepresentation 700, on the left is the front portion of the clientdevice 102 that includes the touchscreen covered, at least in part, bythe conductive material 810, and on the right is the back portion 520 ofthe client device 102 that includes the trackpad (e.g., touch-sensitivecomponent). The touchscreen may present a graphical user interface, suchas a webpage of a particular application, such as a browser application.The trackpad on the back of the client device 102 includes atwo-dimensional array or matrix of touch sensors 720 that detectphysical touch by a user. For example, the touch sensors 720 includecapacitors and when one or a group of capacitors change charge, thetrackpad determines that a position associated with the group ofcapacitors has been physically touched by a user.

In response to detecting the physical touch, the client device 102transmits an electrical signal representing the physical touch of thetouch-sensitive component on the back portion 520 of the client deviceto the touch-sensitive display screen of the front portion of the clientdevice, at operation 1002. For example, a first set of electricalconnections 732, such as using one or more metal or conductive wires514, is formed between a first set of touch sensors of the touchpad onthe back of the client device 102 and a respective capacitor 612 in afirst portion 712 (e.g., a top portion) of the one-dimensional array ofcapacitors 710 on the front of the device via the conductive material810. When a user physically touches a first collection of sensors 722 onthe back of the client device 102, an electrical signal is sent to theelectrically coupled corresponding capacitors 718 and 716 of thetouchscreen on the front of the client device 102 through or via theconductive material 810 that is placed on top of the capacitors 718 and716.

At operation 1003, the client device 102 causes an operation associatedwith the graphical user interface to be executed in response to thetouch-sensitive display screen receiving the electrical signalrepresenting the physical touch of the touch-sensitive component on theback portion 520 of the client device 102. For example, an applicationrunning on the client device 102 that displays content on thetouchscreen can perform an operation associated with receiving a touchinput of the combination of capacitors 718 and 716, such as scrollingthe display up/down when the touchpad detects touch input that drags afinger or swipes a finger up/down.

Machine Architecture

FIG. 11 is a diagrammatic representation of the machine 1100 withinwhich instructions 1108 (e.g., software, a program, an application, anapplet, an app, or other executable code) for causing the machine 1100to perform any one or more of the methodologies discussed herein may beexecuted. For example, the instructions 1108 may cause the machine 1100to execute any one or more of the methods described herein. Theinstructions 1108 transform the general, non-programmed machine 1100into a particular machine 1100 programmed to carry out the described andillustrated functions in the manner described. The machine 1100 mayoperate as a standalone device or may be coupled (e.g., networked) toother machines. In a networked deployment, the machine 1100 may operatein the capacity of a server machine or a client machine in aserver-client network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine 1100 maycomprise, but not be limited to, a server computer, a client computer, apersonal computer (PC), a tablet computer, a laptop computer, a netbook,a set-top box (STB), a personal digital assistant (PDA), anentertainment media system, a cellular telephone, a smartphone, a mobiledevice, a wearable device (e.g., a smartwatch), a smart home device(e.g., a smart appliance), other smart devices, a web appliance, anetwork router, a network switch, a network bridge, or any machinecapable of executing the instructions 1108, sequentially or otherwise,that specify actions to be taken by the machine 1100. Further, whileonly a single machine 1100 is illustrated, the term “machine” shall alsobe taken to include a collection of machines that individually orjointly execute the instructions 1108 to perform any one or more of themethodologies discussed herein. The machine 1100, for example, maycomprise the client device 102 or any one of a number of server devicesforming part of the messaging server system 108. In some examples, themachine 1100 may also comprise both client and server systems, withcertain operations of a particular method or algorithm being performedon the server-side and with certain operations of the particular methodor algorithm being performed on the client-side.

The machine 1100 may include processors 1102, memory 1104, andinput/output (I/O) components 1138, which may be configured tocommunicate with each other via a bus 1140. In an example, theprocessors 1102 (e.g., a central processing unit (CPU), a reducedinstruction set computing (RISC) processor, a complex instruction setcomputing (CISC) processor, a graphics processing unit (GPU), a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a radio-frequency integrated circuit (RFIC), another processor,or any suitable combination thereof) may include, for example, aprocessor 1106 and a processor 1110 that execute the instructions 1108.The term “processor” is intended to include multi-core processors 1102that may comprise two or more independent processors 1106, 1110(sometimes referred to as “cores”) that may execute instructions 1108contemporaneously. Although FIG. 11 shows multiple processors 1102, themachine 1100 may include a single processor 1106 with a single core, asingle processor 1106 with multiple cores (e.g., a multi-coreprocessor), multiple processors 1102 with a single core, multipleprocessors 1102 with multiples cores, or any combination thereof.

The memory 1104 includes a main memory 1112, a static memory 1114, and astorage unit 1116, all accessible to the processors 1102 via the bus1140. The main memory 1112, the static memory 1114, and the storage unit1116 store the instructions 1108 embodying any one or more of themethodologies or functions described herein. The instructions 1108 mayalso reside, completely or partially, within the main memory 1112,within the static memory 1114, within machine-readable medium 1118within the storage unit 1116, within at least one of the processors 1102(e.g., within the processor's cache memory), or any suitable combinationthereof, during execution thereof by the machine 1100.

The I/O components 1138 may include a wide variety of components toreceive input, provide output, produce output, transmit information,exchange information, capture measurements, and so on. The specific I/Ocomponents 1138 that are included in a particular machine will depend onthe type of machine. For example, portable machines such as mobilephones may include a touch input device or other such input mechanisms,while a headless server machine will likely not include such a touchinput device. It will be appreciated that the I/O components 1138 mayinclude many other components that are not shown in FIG. 11 . In variousexamples, the I/O components 1138 may include user output components1124 and user input components 1126. The user output components 1124 mayinclude visual components (e.g., a display such as a plasma displaypanel (PDP), a light-emitting diode (LED) display, a liquid crystaldisplay (LCD), a projector, or a cathode ray tube (CRT)), acousticcomponents (e.g., speakers), haptic components (e.g., a vibratory motor,resistance mechanisms), other signal generators, and so forth. The userinput components 1126 may include alphanumeric input components (e.g., akeyboard, a touch screen configured to receive alphanumeric input, aphoto-optical keyboard, or other alphanumeric input components),point-based input components (e.g., a mouse, a touchpad, a trackball, ajoystick, a motion sensor, or another pointing instrument), tactileinput components (e.g., a physical button, a touch screen that provideslocation and force of touches or touch gestures, or other tactile inputcomponents), audio input components (e.g., a microphone), and the like.

In further examples, the I/O components 1138 may include biometriccomponents 1128, motion components 1130, environmental components 1132,or position components 1134, among a wide array of other components. Forexample, the biometric components 1128 include components to detectexpressions (e.g., hand expressions, facial expressions, vocalexpressions, body gestures, or eye-tracking), measure biosignals (e.g.,blood pressure, heart rate, body temperature, perspiration, or brainwaves), identify a person (e.g., voice identification, retinalidentification, facial identification, fingerprint identification, orelectroencephalogram-based identification), and the like. The motioncomponents 1130 include acceleration sensor components (e.g.,accelerometer), gravitation sensor components, rotation sensorcomponents (e.g., gyroscope).

The environmental components 1132 include, for example, one or morecameras (with still image/photograph and video capabilities),illumination sensor components (e.g., photometer), temperature sensorcomponents (e.g., one or more thermometers that detect ambienttemperature), humidity sensor components, pressure sensor components(e.g., barometer), acoustic sensor components (e.g., one or moremicrophones that detect background noise), proximity sensor components(e.g., infrared sensors that detect nearby objects), gas sensors (e.g.,gas detection sensors to detection concentrations of hazardous gases forsafety or to measure pollutants in the atmosphere), or other componentsthat may provide indications, measurements, or signals corresponding toa surrounding physical environment.

With respect to cameras, the client device 102 may have a camera systemcomprising, for example, front cameras on a front surface of the clientdevice 102 and rear cameras on a rear surface of the client device 102.The front cameras may, for example, be used to capture still images andvideo of a user of the client device 102 (e.g., “selfies”), which maythen be augmented with augmentation data (e.g., filters) describedabove. The rear cameras may, for example, be used to capture stillimages and videos in a more traditional camera mode, with these imagessimilarly being augmented with augmentation data. In addition to frontand rear cameras, the client device 102 may also include a 360° camerafor capturing 360° photographs and videos.

Further, the camera system of a client device 102 may include dual rearcameras (e.g., a primary camera as well as a depth-sensing camera), oreven triple, quad or penta rear camera configurations on the front andrear sides of the client device 102. These multiple camera systems mayinclude a wide camera, an ultra-wide camera, a telephoto camera, a macrocamera, and a depth sensor, for example.

The position components 1134 include location sensor components (e.g., aGPS receiver component), altitude sensor components (e.g., altimeters orbarometers that detect air pressure from which altitude may be derived),orientation sensor components (e.g., magnetometers), and the like.

Communication may be implemented using a wide variety of technologies.The I/O components 1138 further include communication components 1136operable to couple the machine 1100 to a network 1120 or devices 1122via respective coupling or connections. For example, the communicationcomponents 1136 may include a network interface component or anothersuitable device to interface with the network 1120. In further examples,the communication components 1136 may include wired communicationcomponents, wireless communication components, cellular communicationcomponents, Near Field Communication (NFC) components, Bluetooth®components (e.g., Bluetooth® Low Energy), WiFi® components, and othercommunication components to provide communication via other modalities.The devices 1122 may be another machine or any of a wide variety ofperipheral devices (e.g., a peripheral device coupled via a USB).

Moreover, the communication components 1136 may detect identifiers orinclude components operable to detect identifiers. For example, thecommunication components 1136 may include Radio Frequency Identification(RFID) tag reader components, NFC smart tag detection components,optical reader components (e.g., an optical sensor to detectone-dimensional bar codes such as Universal Product Code (UPC) bar code,multi-dimensional bar codes such as Quick Response (QR) code, Azteccode, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2Dbar code, and other optical codes), or acoustic detection components(e.g., microphones to identify tagged audio signals). In addition, avariety of information may be derived via the communication components1136, such as location via Internet Protocol (IP) geolocation, locationvia Wi-Fi® signal triangulation, location via detecting an NFC beaconsignal that may indicate a particular location, and so forth.

The various memories (e.g., main memory 1112, static memory 1114, andmemory 1104 of the processors 1102) and storage unit 1116 may store oneor more sets of instructions 1108 and data structures (e.g., software)embodying or used by any one or more of the methodologies or functionsdescribed herein. These instructions (e.g., the instructions 1108), whenexecuted by processors 1102, cause various operations to implement thedisclosed examples.

The instructions 1108 may be transmitted or received over the network1120, using a transmission medium, via a network interface device (e.g.,a network interface component included in the communication components1136) and using any one of several well-known transfer protocols (e.g.,hypertext transfer protocol (HTTP)). Similarly, the instructions 1108may be transmitted or received using a transmission medium via acoupling (e.g., a peer-to-peer coupling) to the devices 1122.

Software Architecture

FIG. 12 is a block diagram 1200 illustrating a software architecture1204, which can be installed on any one or more of the devices describedherein. The software architecture 1204 is supported by hardware such asa machine 1202 that includes processors 1220, memory 1226, and I/Ocomponents 1238. In this example, the software architecture 1204 can beconceptualized as a stack of layers, where each layer provides aparticular functionality. The software architecture 1204 includes layerssuch as an operating system 1212, libraries 1210, frameworks 1208, andapplications 1206. Operationally, the applications 1206 invoke API calls1250 through the software stack and receive messages 1252 in response tothe API calls 1250.

The operating system 1212 manages hardware resources and provides commonservices. The operating system 1212 includes, for example, a kernel1214, services 1216, and drivers 1222. The kernel 1214 acts as anabstraction layer between the hardware and the other software layers.For example, the kernel 1214 provides memory management, processormanagement (e.g., scheduling), component management, networking, andsecurity settings, among other functionality. The services 1216 canprovide other common services for the other software layers. The drivers1222 are responsible for controlling or interfacing with the underlyinghardware. For instance, the drivers 1222 can include display drivers,camera drivers, BLUETOOTH® or BLUETOOTH® Low Energy drivers, flashmemory drivers, serial communication drivers (e.g., USB drivers), WI-FI®drivers, audio drivers, power management drivers, and so forth.

The libraries 1210 provide a common low-level infrastructure used by theapplications 1206. The libraries 1210 can include system libraries 1218(e.g., C standard library) that provide functions such as memoryallocation functions, string manipulation functions, mathematicfunctions, and the like. In addition, the libraries 1210 can include APIlibraries 1224 such as media libraries (e.g., libraries to supportpresentation and manipulation of various media formats such as MovingPicture Experts Group-4 (MPEG4), Advanced Video Coding (H.264 or AVC),Moving Picture Experts Group Layer-3 (MP3), Advanced Audio Coding (AAC),Adaptive Multi-Rate (AMR) audio codec, Joint Photographic Experts Group(JPEG or JPG), or Portable Network Graphics (PNG)), graphics libraries(e.g., an OpenGL framework used to render in two dimensions (2D) andthree dimensions (3D) in a graphic content on a display), databaselibraries (e.g., SQLite to provide various relational databasefunctions), web libraries (e.g., WebKit to provide web browsingfunctionality), and the like. The libraries 1210 can also include a widevariety of other libraries 1228 to provide many other APIs to theapplications 1206.

The frameworks 1208 provide a common high-level infrastructure that isused by the applications 1206. For example, the frameworks 1208 providevarious graphical user interface (GUI) functions, high-level resourcemanagement, and high-level location services. The frameworks 1208 canprovide a broad spectrum of other APIs that can be used by theapplications 1206, some of which may be specific to a particularoperating system 1212 or platform.

In an example, the applications 1206 may include a home application1236, a contacts application 1230, a browser application 1232, a bookreader application 1234, a location application 1242, a mediaapplication 1244, a messaging application 1246, a game application 1248,and a broad assortment of other applications such as a third-partyapplication 1240. The applications 1206 are programs that executefunctions defined in the programs. Various programming languages can beemployed to create one or more of the applications 1206, structured in avariety of manners, such as object-oriented programming languages (e.g.,Objective-C, Java, or C++) or procedural programming languages (e.g., Cor assembly language). In a specific example, the third-partyapplication 1240 (e.g., an application developed using the ANDROID™ orIOS™ software development kit (SDK) by an entity other than the vendorof the particular platform) may be mobile software running on a mobileoperating system such as IOS™, ANDROID™, WINDOWS® Phone, or anothermobile operating system. In this example, the third-party application1240 can invoke the API calls 1250 provided by the operating system 1212to facilitate functionality described herein.

Glossary

“Carrier signal” refers to any intangible medium that is capable ofstoring, encoding, or carrying instructions for execution by themachine, and includes digital or analog communications signals or otherintangible media to facilitate communication of such instructions.Instructions may be transmitted or received over a network using atransmission medium via a network interface device.

“Client device” refers to any machine that interfaces to acommunications network to obtain resources from one or more serversystems or other client devices. A client device may be, but is notlimited to, a mobile phone, desktop computer, laptop, portable digitalassistants (PDAs), smartphones, tablets, ultrabooks, netbooks, laptops,multi-processor systems, microprocessor-based or programmable consumerelectronics, game consoles, set-top boxes, or any other communicationdevice that a user may use to access a network.

“Communication network” refers to one or more portions of a network thatmay be an ad hoc network, an intranet, an extranet, a virtual privatenetwork (VPN), a local area network (LAN), a wireless LAN (WLAN), a widearea network (WAN), a wireless WAN (WWAN), a metropolitan area network(MAN), the Internet, a portion of the Internet, a portion of the PublicSwitched Telephone Network (PSTN), a plain old telephone service (POTS)network, a cellular telephone network, a wireless network, a Wi-Fi®network, another type of network, or a combination of two or more suchnetworks. For example, a network or a portion of a network may include awireless or cellular network and the coupling may be a Code DivisionMultiple Access (CDMA) connection, a Global System for Mobilecommunications (GSM) connection, or other types of cellular or wirelesscoupling. In this example, the coupling may implement any of a varietyof types of data transfer technology, such as Single Carrier RadioTransmission Technology (1×RTT), Evolution-Data Optimized (EVDO)technology, General Packet Radio Service (GPRS) technology, EnhancedData rates for GSM Evolution (EDGE) technology, third GenerationPartnership Project (3GPP) including 3G, fourth generation wireless (4G)networks, Universal Mobile Telecommunications System (UMTS), High SpeedPacket Access (HSPA), Worldwide Interoperability for Microwave Access(WiMAX), Long Term Evolution (LTE) standard, others defined by variousstandard-setting organizations, other long-range protocols, or otherdata transfer technology.

“Component” refers to a device, physical entity, or logic havingboundaries defined by function or subroutine calls, branch points, APIs,or other technologies that provide for the partitioning ormodularization of particular processing or control functions. Componentsmay be combined via their interfaces with other components to carry outa machine process. A component may be a packaged functional hardwareunit designed for use with other components and a part of a program thatusually performs a particular function of related functions.

Components may constitute either software components (e.g., codeembodied on a machine-readable medium) or hardware components. A“hardware component” is a tangible unit capable of performing certainoperations and may be configured or arranged in a certain physicalmanner. In various example embodiments, one or more computer systems(e.g., a standalone computer system, a client computer system, or aserver computer system) or one or more hardware components of a computersystem (e.g., a processor or a group of processors) may be configured bysoftware (e.g., an application or application portion) as a hardwarecomponent that operates to perform certain operations as describedherein.

A hardware component may also be implemented mechanically,electronically, or any suitable combination thereof. For example, ahardware component may include dedicated circuitry or logic that ispermanently configured to perform certain operations. A hardwarecomponent may be a special-purpose processor, such as afield-programmable gate array (FPGA) or an application specificintegrated circuit (ASIC). A hardware component may also includeprogrammable logic or circuitry that is temporarily configured bysoftware to perform certain operations. For example, a hardwarecomponent may include software executed by a general-purpose processoror other programmable processor. Once configured by such software,hardware components become specific machines (or specific components ofa machine) uniquely tailored to perform the configured functions and areno longer general-purpose processors. It will be appreciated that thedecision to implement a hardware component mechanically, in dedicatedand permanently configured circuitry, or in temporarily configuredcircuitry (e.g., configured by software), may be driven by cost and timeconsiderations. Accordingly, the phrase “hardware component” (or“hardware-implemented component”) should be understood to encompass atangible entity, be that an entity that is physically constructed,permanently configured (e.g., hardwired), or temporarily configured(e.g., programmed) to operate in a certain manner or to perform certainoperations described herein.

Considering embodiments in which hardware components are temporarilyconfigured (e.g., programmed), each of the hardware components need notbe configured or instantiated at any one instance in time. For example,where a hardware component comprises a general-purpose processorconfigured by software to become a special-purpose processor, thegeneral-purpose processor may be configured as respectively differentspecial-purpose processors (e.g., comprising different hardwarecomponents) at different times. Software accordingly configures aparticular processor or processors, for example, to constitute aparticular hardware component at one instance of time and to constitutea different hardware component at a different instance of time.

Hardware components can provide information to, and receive informationfrom, other hardware components. Accordingly, the described hardwarecomponents may be regarded as being communicatively coupled. Wheremultiple hardware components exist contemporaneously, communications maybe achieved through signal transmission (e.g., over appropriate circuitsand buses) between or among two or more of the hardware components. Inembodiments in which multiple hardware components are configured orinstantiated at different times, communications between such hardwarecomponents may be achieved, for example, through the storage andretrieval of information in memory structures to which the multiplehardware components have access. For example, one hardware component mayperform an operation and store the output of that operation in a memorydevice to which it is communicatively coupled. A further hardwarecomponent may then, at a later time, access the memory device toretrieve and process the stored output. Hardware components may alsoinitiate communications with input or output devices, and can operate ona resource (e.g., a collection of information).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implementedcomponents that operate to perform one or more operations or functionsdescribed herein. As used herein, “processor-implemented component”refers to a hardware component implemented using one or more processors.Similarly, the methods described herein may be at least partiallyprocessor-implemented, with a particular processor or processors beingan example of hardware. For example, at least some of the operations ofa method may be performed by one or more processors 1102 orprocessor-implemented components. Moreover, the one or more processorsmay also operate to support performance of the relevant operations in a“cloud computing” environment or as a “software as a service” (SaaS).For example, at least some of the operations may be performed by a groupof computers (as examples of machines including processors), with theseoperations being accessible via a network (e.g., the Internet) and viaone or more appropriate interfaces (e.g., an API). The performance ofcertain of the operations may be distributed among the processors, notonly residing within a single machine, but deployed across a number ofmachines. In some example embodiments, the processors orprocessor-implemented components may be located in a single geographiclocation (e.g., within a home environment, an office environment, or aserver farm). In other example embodiments, the processors orprocessor-implemented components may be distributed across a number ofgeographic locations.

“Computer-readable storage medium” refers to both machine-storage mediaand transmission media. Thus, the terms include both storagedevices/media and carrier waves/modulated data signals. The terms“machine-readable medium,” “computer-readable medium” and“device-readable medium” mean the same thing and may be usedinterchangeably in this disclosure.

“Ephemeral message” refers to a message that is accessible for atime-limited duration. An ephemeral message may be a text, an image, avideo and the like. The access time for the ephemeral message may be setby the message sender. Alternatively, the access time may be a defaultsetting or a setting specified by the recipient. Regardless of thesetting technique, the message is transitory.

“Machine storage medium” refers to a single or multiple storage devicesand media (e.g., a centralized or distributed database, and associatedcaches and servers) that store executable instructions, routines anddata. The term shall accordingly be taken to include, but not be limitedto, solid-state memories, and optical and magnetic media, includingmemory internal or external to processors. Specific examples ofmachine-storage media, computer-storage media and device-storage mediainclude non-volatile memory, including by way of example semiconductormemory devices, e.g., erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), FPGA, andflash memory devices; magnetic disks such as internal hard disks andremovable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks Theterms “machine-storage medium,” “device-storage medium,”“computer-storage medium” mean the same thing and may be usedinterchangeably in this disclosure. The terms “machine-storage media,”“computer-storage media,” and “device-storage media” specificallyexclude carrier waves, modulated data signals, and other such media, atleast some of which are covered under the term “signal medium.”

“Non-transitory computer-readable storage medium” refers to a tangiblemedium that is capable of storing, encoding, or carrying theinstructions for execution by a machine.

“Signal medium” refers to any intangible medium that is capable ofstoring, encoding, or carrying the instructions for execution by amachine and includes digital or analog communications signals or otherintangible media to facilitate communication of software or data. Theterm “signal medium” shall be taken to include any form of a modulateddata signal, carrier wave, and so forth. The term “modulated datasignal” means a signal that has one or more of its characteristics setor changed in such a matter as to encode information in the signal. Theterms “transmission medium” and “signal medium” mean the same thing andmay be used interchangeably in this disclosure.

Changes and modifications may be made to the disclosed embodimentswithout departing from the scope of the present disclosure. These andother changes or modifications are intended to be included within thescope of the present disclosure, as expressed in the following claims.

What is claimed is:
 1. A method comprising: storing a many-to-onecorrespondence between a first plurality of touch sensors of a touchsensitive component on a back portion of a client device and a firstcapacitor on a touch-sensitive display screen of a front portion of theclient device; and in response to detecting simultaneous physical touchof the first plurality of touch sensors, transmitting an electricalsignal representing the simultaneous physical touch to the firstcapacitor, the first capacitor comprising a conductive element of aplurality of conductive elements associated with the touch-sensitivedisplay screen of the front portion of the client device.
 2. The methodof claim 1, wherein the client device displays a graphical userinterface on the touch-sensitive display screen of the front portion ofthe client device, further comprising: causing an operation associatedwith the graphical user interface to be executed in response to thetouch-sensitive display screen receiving the electrical signalrepresenting the simultaneous physical touch of the first plurality oftouch sensors of the touch-sensitive component on the back portion ofthe client device.
 3. The method of claim 1, wherein the touch-sensitivecomponent on the back portion of the client device is electricallycoupled to the touch-sensitive display screen of the front portion ofthe client device, wherein a first group of multiple touch sensors onthe touch-sensitive component on the back portion of the client deviceis associated with a first conductive element of the touch-sensitivedisplay screen, and wherein a second group of multiple touch sensors onthe touch-sensitive component on the back portion of the client deviceis associated with a second conductive element of the touch-sensitivedisplay screen.
 4. The method of claim 1, further comprising scrolling adisplay of a web browser in a direction corresponding to a swipegesture.
 5. The method of claim 1, wherein the touch-sensitive displayscreen of the front portion of the client device comprises a transparentlayer overlaying at least a portion of the touch-sensitive displayscreen, the transparent layer comprising a two-dimensional array ofconductors.
 6. The method of claim 5, wherein the transparent layercomprises conductive material.
 7. The method of claim 5, wherein thetouch-sensitive component comprises a plurality of touch sensors.
 8. Themethod of claim 1, further comprising toggling a physical switch tooperatively and selectively disconnect electric coupling between thetouch-sensitive component and the touch-sensitive display screen,wherein when the physical switch is in an inactive state, physical touchof a given touch sensor of the touch-sensitive component does not causea corresponding capacitor of the touch-sensitive display screen to bedischarged.
 9. The method of claim 1, further comprising toggling aphysical switch to modify a pattern of the touch-sensitive displayscreen associated with the touch-sensitive component.
 10. The method ofclaim 9, further comprising: setting the physical switch to activate afirst pattern in which a first touch sensor of the touch-sensitivecomponent is electrically coupled to a first portion of thetouch-sensitive display screen; and toggling the physical switch toactivate a second pattern in which the first touch sensor of thetouch-sensitive component is electrically coupled to a second portion ofthe touch-sensitive display screen.
 11. The method of claim 10, whereinthe first pattern corresponds to an arrangement of keys of a musicalinstrument or game controller.
 12. The method of claim 1, furthercomprising activating and deactivating the touch-sensitive component bymanipulating an analog switch.
 13. The method of claim 12, wherein theanalog switch comprises a push button or a toggle button.
 14. The methodof claim 1, wherein the touch-sensitive component comprises a firsttouch-sensitive component with a first arrangement of touch sensors, andwherein a second touch-sensitive component is configured to replace thefirst touch-sensitive component, the second touch-sensitive componentcomprising a second arrangement of touch sensors.
 15. The method ofclaim 1, wherein the touch-sensitive display screen of the front portionof the client device comprises a transparent layer overlaying at least aportion of the touch-sensitive display screen, the transparent layercomprising indium tin oxide (ITO).
 16. A system comprising: a processorconfigured to perform operations comprising: storing a many-to-onecorrespondence between a first plurality of touch sensors of a touchsensitive component on a back portion of a client device and a firstcapacitor on a touch-sensitive display screen of a front portion of theclient device; and in response to detecting simultaneous physical touchof the first plurality of touch sensors, transmitting an electricalsignal representing the simultaneous physical touch to the firstcapacitor, the first capacitor comprising a conductive element of aplurality of conductive elements associated with the touch-sensitivedisplay screen of the front portion of the client device.
 17. The systemof claim 16, wherein the client device displays a graphical userinterface on the touch-sensitive display screen of the front portion ofthe client device, the operations further comprising: causing anoperation associated with the graphical user interface to be executed inresponse to the touch-sensitive display screen receiving the electricalsignal representing the simultaneous physical touch of the firstplurality of touch sensors of the touch-sensitive component on the backportion of the client device.
 18. The system of claim 16, wherein thetouch-sensitive component on the back portion of the client device iselectrically coupled to the touch-sensitive display screen of the frontportion of the client device, wherein a first group of multiple touchsensors on the touch-sensitive component on the back portion of theclient device is associated with a first conductive element of thetouch-sensitive display screen, and wherein a second group of multipletouch sensors on the touch-sensitive component on the back portion ofthe client device is associated with a second conductive element of thetouch-sensitive display screen.
 19. The system of claim 16, theoperations further comprising scrolling a display of a web browser in adirection corresponding to a swipe gesture.
 20. A non-transitorymachine-readable storage medium that includes instructions that, whenexecuted by one or more processors of a machine, cause the machine toperform operations comprising: storing a many-to-one correspondencebetween a first plurality of touch sensors of a touch sensitivecomponent on a back portion of a client device and a first capacitor ona touch-sensitive display screen of a front portion of the clientdevice; and in response to detecting simultaneous physical touch of thefirst plurality of touch sensors, transmitting an electrical signalrepresenting the simultaneous physical touch to the first capacitor, thefirst capacitor comprising a conductive element of a plurality ofconductive elements associated with the touch-sensitive display screenof the front portion of the client device.